US4887911A - Developer mixer for electrophotographic copying machine - Google Patents

Developer mixer for electrophotographic copying machine Download PDF

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Publication number
US4887911A
US4887911A US07/253,319 US25331988A US4887911A US 4887911 A US4887911 A US 4887911A US 25331988 A US25331988 A US 25331988A US 4887911 A US4887911 A US 4887911A
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Prior art keywords
shaft
fins
developer
mixer
fin
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Expired - Lifetime
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US07/253,319
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English (en)
Inventor
Takashi Miyaji
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Sharp Corp
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Sharp Corp
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Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
    • B01F27/05—Stirrers
    • B01F27/11—Stirrers characterised by the configuration of the stirrers
    • B01F27/112—Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades
    • B01F27/1125—Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades with vanes or blades extending parallel or oblique to the stirrer axis
    • B01F27/11253—Stirrers characterised by the configuration of the stirrers with arms, paddles, vanes or blades with vanes or blades extending parallel or oblique to the stirrer axis the blades extending oblique to the stirrer axis

Definitions

  • This invention relates to a mixing device for the developing station in an electrophotographic copying machine and more particularly to a developer mixer comprising a mixer roller rotatably mounted in a developer tank and having a plurality of fins with missing radial sections.
  • the developing station in an electrophotographic copying machine generally uses a two-component developer containing a carrier and a toner to develop a latent image formed on a photosensitive drum.
  • a developing station typically includes a developer roller 2 and a mixer roller 3 disposed inside a tank 1 such that the toner supplied from a hopper 4 is mixed with the carrier inside the tank by the agitating motion of the mixer roller 3 and the developer thus mixed is applied to the photosensitive drum 5 by means of the developer roller 3.
  • a developing station of this type includes only one mixer roller 3, such a roller must be able to efficiently mix the developer components together by rotating around its axis.
  • the applicant herein developed a mixing device which, as shown in FIG.
  • a shaft 10 rotatably disposed inside a tank (not shown) and a plurality of fins A-L with missing radial sections attached obliquely to this shaft such that the missing sections of adjacent fins are at opposite directions with respect to the shaft but that the surfaces of the fins are mutually parallel.
  • the shaft 10 is rotated in the direction shown by the circular arrows, the developer liquid in the region i, for example, is pushed to the left by the second fin B and moves as shown by the arrow a through the missing radial section of the first fin A.
  • the portion of the liquid in the region i pushed by the first fin A moves as shown by the arrow b through the missing radial section of the second fin B.
  • the liquid in the region iii is either pressed by the fourth fin D and moves to the region ii along the arrow c or pushed by the third fin C and moves in the direction of the arrow d.
  • the amount of liquid increases in the region ii but decreases in the regions i and iii.
  • the amount of liquid in the region ii reaches a certain level, it begins to flow over into the neighboring regions i and iii. Similar phenomena take place in the other regions along the shaft 10 as it rotates and the developer liquid becomes mixed together efficiently inside the tank.
  • a developer mixer comprising a shaft which is rotatably mounted in a developer tank and a plurality of metallic fins each with a notched periphery and a missing radial section attached obliquely to the shaft such that the missing radial sections of adjacent fins are at opposite directions with respect to the shaft. Since the fins are made of a metallic material, electrostatic charging takes place inside the tank only between the carrier and the toner. Since there is no charging between the toner and the fins, there is no generation of oppositely charged toners and hence a clear image without fogginess can be obtained.
  • the notches provided at the peripheries of the fins serve to reduce the effects of centrifugal forces in the peripheral regions of the fins and thereby prevent the reduction in the rate of flow of the developer liquid toward the shaft.
  • the notches at the peripheries of the fins further serve to provide twisting forces on the liquid and this has the effect of improving the efficiency of mixing.
  • the shaft can be rotated at a faster rate without incurring disadvantageous effects encountered in the case of a previously developed mixer shown in FIG. 5.
  • FIG. 1 is a front view of a developer mixer according to an embodiment of the present invention
  • FIG. 2 is a top view of a portion of the mixer of FIG. 1 around the fin B',
  • FIG. 3 is a front view of one of the fins
  • FIG. 4 is a drawing showing the position of a developing station incorporating the mixer of this invention with respect to the photosensitive drum of an electrophotographic copying machine of which this developing station is a part,
  • FIG. 5 is a side view of a developer mixer developed prior to the present invention.
  • FIG. 6 is a drawing showing the problem of fogginess encountered with a prior art developer mixer in an electrophotographic copying machine.
  • FIGS. 1 and 2 there is shown a developer mixer according to one embodiment of the present invention having a total of six fins A'-F' and a shaft 10'.
  • the shaft 10' is supported at both ends by side walls of a developer tank (not shown) and the left-hand end is connected to a driving means which causes the shaft 10' to rotate in the direction indicated by a circular double arrow.
  • Each fin is shaped as shown in FIG. 3, being an approximately elliptical metal plate with a radially extending portion P removed and having a plurality of notches Q along the periphery.
  • a connecting section 20 for attaching the fin to the shaft 10' obliquely at an angle ⁇ as shown in FIG. 1 by means of a screw 21 and a nut 22.
  • FIG. 1 also shows that the fins are attached to the shaft 10' in such ways that the removed portions P of adjacent fins are at opposite directions with respect to the shaft 10'
  • portions of the liquid in this region flow through the notches Q into the region between the fins A' and B, Similarly, a portion of the liquid in the peripheral region of the fin C' flows into the region between the fins B' and C' Phenomena similar to these occur with respect to all fins, and this means that these portions of liquid are not forced to move away from the shaft 10' by centrifugal force and hence that the liquid can be mixed together efficiently. Moreover, portions of the liquid flowing through the notches Q as shown by the arrows k experience a twisting force by the rotation of the obliquely mounted fin and this has the effect of more efficiently mixing the liquid.
  • the liquid in the tank is subjected to a very complicated combination of forces and hence becomes mixed together efficiently without being forced to move away from the shaft by centrifugal force.
  • the fins A'-F' are made of a metallic material, furthermore, there is no electric charging by friction between the fins and the toner or the carrier. This additionally has the favorable effect of preventing the generation of oppositely charged toners.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dry Development In Electrophotography (AREA)
  • Wet Developing In Electrophotography (AREA)
US07/253,319 1985-06-21 1988-09-30 Developer mixer for electrophotographic copying machine Expired - Lifetime US4887911A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP60-94746 1985-06-21
JP1985094746U JPS622061U (de) 1985-06-21 1985-06-21

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US07120229 Continuation 1987-11-10

Publications (1)

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US4887911A true US4887911A (en) 1989-12-19

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US07/253,319 Expired - Lifetime US4887911A (en) 1985-06-21 1988-09-30 Developer mixer for electrophotographic copying machine

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US (1) US4887911A (de)
JP (1) JPS622061U (de)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5025287A (en) * 1989-12-18 1991-06-18 Eastman Kodak Company Development apparatus having dual interleaving paddle mixers
US5151288A (en) * 1990-10-16 1992-09-29 Besst Frozen Products, Inc. Food processing apparatus and method
EP0515852A1 (de) * 1991-05-31 1992-12-02 EKATO Rühr- und Mischtechnik GmbH Rührvorrichtung
US5229150A (en) * 1990-10-16 1993-07-20 Besst Frozen Products, Inc. Food processing apparatus and method
US5342124A (en) * 1993-02-12 1994-08-30 Cmi Corporation Mixer having blades arranged in a discontinuous helical pattern
US5348753A (en) * 1990-10-16 1994-09-20 Besst Frozen Products, Inc. Food processing apparatus and method
US5887976A (en) * 1996-04-19 1999-03-30 Sintokogio, Ltd. Continuous kneading machine having at least one rotating shaft and paddles and notched adjusting plates mounted on each shaft
US6647235B2 (en) * 2001-06-29 2003-11-11 Heidelberger Druckmaschinen Ag Mechanism for agitating the toner in the replenisher of an electrophotographic machine
US20080298171A1 (en) * 2007-05-08 2008-12-04 David Scott Dunlop Process for Mixing and Screening Liquid Compositions
US20110255364A1 (en) * 2009-09-04 2011-10-20 Tsukasa Co., Ltd. Powder/particulate material agitator

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2720384A (en) * 1953-06-10 1955-10-11 Armstrong Cork Co Conveyor system
US4146323A (en) * 1977-06-29 1979-03-27 Xerox Corporation Auger for a development system
US4576466A (en) * 1982-03-24 1986-03-18 Konishiroku Photo Industry Co., Ltd. Developing system for an electrostatic copying apparatus
US4583842A (en) * 1983-10-19 1986-04-22 Kabushiki Kaisha Toshiba Developing apparatus

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS587155B2 (ja) * 1977-05-12 1983-02-08 三洋電機株式会社 棚装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2720384A (en) * 1953-06-10 1955-10-11 Armstrong Cork Co Conveyor system
US4146323A (en) * 1977-06-29 1979-03-27 Xerox Corporation Auger for a development system
US4576466A (en) * 1982-03-24 1986-03-18 Konishiroku Photo Industry Co., Ltd. Developing system for an electrostatic copying apparatus
US4583842A (en) * 1983-10-19 1986-04-22 Kabushiki Kaisha Toshiba Developing apparatus

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5025287A (en) * 1989-12-18 1991-06-18 Eastman Kodak Company Development apparatus having dual interleaving paddle mixers
US5151288A (en) * 1990-10-16 1992-09-29 Besst Frozen Products, Inc. Food processing apparatus and method
US5229150A (en) * 1990-10-16 1993-07-20 Besst Frozen Products, Inc. Food processing apparatus and method
US5348753A (en) * 1990-10-16 1994-09-20 Besst Frozen Products, Inc. Food processing apparatus and method
EP0515852A1 (de) * 1991-05-31 1992-12-02 EKATO Rühr- und Mischtechnik GmbH Rührvorrichtung
US5342124A (en) * 1993-02-12 1994-08-30 Cmi Corporation Mixer having blades arranged in a discontinuous helical pattern
US5887976A (en) * 1996-04-19 1999-03-30 Sintokogio, Ltd. Continuous kneading machine having at least one rotating shaft and paddles and notched adjusting plates mounted on each shaft
US6647235B2 (en) * 2001-06-29 2003-11-11 Heidelberger Druckmaschinen Ag Mechanism for agitating the toner in the replenisher of an electrophotographic machine
US20080298171A1 (en) * 2007-05-08 2008-12-04 David Scott Dunlop Process for Mixing and Screening Liquid Compositions
US20110255364A1 (en) * 2009-09-04 2011-10-20 Tsukasa Co., Ltd. Powder/particulate material agitator
US8894272B2 (en) * 2009-09-04 2014-11-25 Tsukasa Co., Ltd. Powder material agitator

Also Published As

Publication number Publication date
JPS622061U (de) 1987-01-08

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